This invention relates to medico-surgical collection bags.
The invention is more particularly concerned with filtered bags, such as ostomy bags.
An ostomy bag comprises a bag of flexible plastics material sealed around its edge and having an opening in one face which, in use, is secured around the user's stoma so that discharged material enters the bag. The most convenient way of attaching the bag to the patient is by means of an adhesive region around the bag opening which adheres directly either to the patient's skin or to the front of a separate patient fitment which is secured to the skin. In GB2213728 there is described a bag in which a flange with an adhesive surface is secured to the inside surface of a wall of the bag around its opening, and in which the opening in the wall exposes adhesive on the flange. An external flange is secured to the exposed adhesive region and this is used to secure the bag to the patient. In GB 2247840 there is described a two-part bag assembly in which the bag is adhered to a separate patient fitment.
It is common practice for such bags to have a filtered vent to allow for the escape of gas from the bag, the filter reducing the transmission of ordors. Preferably, the vent should be capable of being completely sealed so that a cushion of gas can be trapped in the bag. This is sometimes necessary to prevent the accumulation of faeces around the stoma and to keep the front wall of the bag away from the stoma to reduce irritation of the stoma.